Apparatus providing a plurality of light beams

ABSTRACT

An apparatus comprises an array of vertical-cavity surface-emitting lasers. Each of the vertical-cavity surface-emitting lasers is configured to be a source of light. The apparatus also comprises an optical arrangement configured to receive light from a plurality of the vertical-cavity surface-emitting lasers and to output a plurality of light beams.

BACKGROUND Technical Field

Some embodiments relate to an apparatus and in particular, but notexclusively, to an apparatus providing a plurality of light beams.

Description of the Related Art

Photosensitive devices are employed in a range of applications, forexample determination of light levels, communications, range detectionetc.

For example single photon avalanche diodes (SPAD) may be used as adetector of reflected light from a light source. In general, an array ofpixels including SPAD sensing elements are provided as a sensor in orderto detect a reflected light pulse from the light source. A photon maygenerate a carrier in the SPAD through the photo electric effect. Thephotogenerated carrier may trigger an avalanche current in one or moreof the SPADs in an SPAD array. The avalanche current may signal anevent, namely that a photon of light has been detected.

The use of SPAD arrays for ranging is well known. For example SPADarrays and SPAD sensors have been used to determine time-of-flightdistances for ranging applications in mobile devices.

The source of the light source may be provided by one or morevertical-cavity surface-emitting laser (VCSEL) diodes.

BRIEF SUMMARY

According to an aspect, there is provided an apparatus comprising: anarray of vertical-cavity surface-emitting lasers, each of saidvertical-cavity surface-emitting lasers being configured to be a sourceof light; and an optical arrangement configured to receive light from aplurality of said vertical-cavity surface-emitting lasers and to outputa plurality of light beams.

The optical arrangement may comprise at least one optical elementconfigured to provide a beam shaping function.

The beam shape may be rectangular.

The optical arrangement may comprise a shared optical element which isconfigured to receive light from each of said vertical-cavitysurface-emitting lasers of said array.

The optical arrangement may comprise a plurality of optical elements, anoptical element being provided for each beam.

The optical arrangement may comprise an array of optical elements withan optical element being provided for each light beam, one or morevertical-cavity surface-emitting lasers providing each light beam.

The optical arrangement may comprises one or more micro-lenses providedon a substrate providing said array of vertical cavity surface-emittinglasers.

The optical arrangement may comprise a plurality of lenses on said arrayof vertical-cavity surface-emitting lasers, one for each of saidvertical-cavity surface-emitting lasers.

The array of vertical-cavity surface-emitting laser may be provided by aplurality of singulated vertical-cavity surface-emitting laser dies.

The optical arrangement may comprise a plurality of micro-lensesprovided on a substrate providing said array of vertical-cavitysurface-emitting lasers and a shared optical element which is configuredto receive light from each of said vertical-cavity surface-emittinglasers of said array.

The optical arrangement may comprise a plurality of micro-lensesprovided on a substrate providing said array of vertical-cavitysurface-emitting lasers and a plurality of further optical components,one further optical component being provided for each beam.

The array of vertical-cavity surface-emitting laser may be provided by aplurality of singulated vertical-cavity surface-emitting laser dies andsaid optical arrangement may comprise a plurality of optical components,one being provided for each beam.

The apparatus may comprise control circuitry configured to control whichof said vertical-cavity surface-emitting lasers are activated

The control circuitry may be configured to control said array ofvertical-cavity surface-emitting laser s to provide said beamssequentially.

According to another aspect, there is provided a detector comprising; anapparatus described previously; and a light detector configured todetect light from said apparatus reflected from one or more objects.

The light detector may comprise an array of single photon avalanchediodes.

The detector may be a ranging detector.

The detector may use time of flight to determine distance to an object.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments will now be described by way of example only and withreference to the accompanying Figures in which:

FIG. 1 shows a schematic view N channels provided by a light source;

FIG. 2 shows a first arrangement for providing N light channels;

FIG. 3 shows a second arrangement for providing N light channels;

FIG. 4 shows a third arrangement for providing N light channels;

FIGS. 5 a and 5 b show a schematic view of potential misalignment of aVCSEL array and optical elements;

FIG. 6 schematically shows an arrangement using a time of flightprinciple; and

FIG. 7 schematically shows a detector of some embodiments.

DETAILED DESCRIPTION

Some embodiments are discussed in detail below. It should beappreciated, however, that the present disclosure provides manyapplicable inventive concepts that can be embodied in a wide variety ofspecific contexts. The specific embodiments discussed are merelyillustrative of specific ways to make and use the disclosed subjectmatter, and do not limit the scope of the different embodiments.

Some embodiments may be provided in devices for determining the distanceto an object. One method is called “Time of Flight” (ToF). This methodcomprises sending a light signal towards the object and measuring thetime taken by the signal to travel to the object and back. Thecalculation of the time taken by the signal for this travel may beobtained by measuring the phase shift between the signal coming out ofthe light source and the signal reflected from the object and detectedby a light sensor. Knowing this phase shift and the speed of lightenables the determination of the distance to the object.

Single photon avalanche diodes (SPAD) may be used as a detector ofreflected light. In general an array of SPADs are provided as a sensorin order to detect a reflected light pulse. A photon may generate acarrier in the SPAD through the photoelectric effect. The photogeneratedcarrier may trigger an avalanche current in one or more of the SPADs inan SPAD array. The avalanche current may signal an event, namely that aphoton of light has been detected.

It should be appreciated that other embodiments may be used with othertypes of detector. By way of example only, some embodiments may be usedwith a fast photodiode based ToF module or in LIDAR (light detection andranging) applications. LIDAR has many applications including consumerelectronics, automotive, robotics, surveying and so on.

An example LIDAR system uses a light source, for example a verticalcavity surface emitting laser (VCSEL), to generate light pulses whichare reflected from a surface and then detected at a receiver ordetector, for example a photodiode or single photon avalanche diode(SPAD) array.

The time difference between the light being transmitted and receivedprovides the distance or range value using the equation D=S*T, where Tis the time difference, S the speed of light and D the distance from thetransmitter to the reflecting object and back again.

FIG. 6 illustrates the general principle of a “Time of Flight” method.In

FIG. 6 , a generator 10 (referenced as box PULSE in FIG. 6 ) provides aperiodic electric signal (for example, square-shaped). This signalpowers a light source 12. An example of a light source 12 may be forexample, a laser diode. The signal coming out of light source 12 istransmitted towards an object 16 and is reflected by this object. Thereflected light signal is detected by a light sensor (shown as box CAPTin FIG. 6 ) 18. The signal on sensor 18, is thus phase-shifted from thesignal provided by the generator for an ideal system by a time periodproportional to twice the distance to object 16 (In practice there isalso electrical to optical delay time from the light source).Calculation block 20 (shown as box DIFF in FIG. 6 ) receives the signalsgenerated by generator 10 and by sensor 18 and calculates the phaseshift between these signals to obtain the distance to object 16.

The light source may be provided by a vertical-cavity surface-emittinglaser (VCSEL). A VCSEL is a semiconductor-based laser diode that emitsan optical beam “vertically” from its top surface. The vertical cavitysurface emitting laser is provided with current by a driver circuitwhich is typically configured to be able to control the current throughthe laser in order to produce pulse or other waveform outputs.

Some embodiments may provide a relatively compact SPAD based ToF system.This may have application in, for example, the mobile consumer market.Other embodiments may be used with other types of detector. Someembodiments may be used in any application which requires a light sourcearrangement. Some of those applications may be without a light detector.

It has been proposed to illuminate a full field of view with a VCSELbased illumination source array and simultaneously reading out a fullframe with a SPAD based sensor array.

However, there may be one or more issues which may be considered. Oneissue may be the power consumption when the full SPAD array is activelyreading out at the same time. Another issue relates to the drive currentto drive the VCSEL array at the same time. To this end, the array may beoperated in a scanning mode. In a scanning mode one or more, but notall, of the rows may be scanned or activated in turn. It should beappreciated that scanning allows for a lower average power versus anequivalent non-scanned implementation.

It should be appreciated that in some embodiments there may be scanningof the array of light sources. In other embodiments, there whole arrayof light sources may be activated at the same time.

One or other or both of these issues may be considered where the SPAD orother detector array and/or VCSEL arrays are larger in size. However, itshould be appreciated that one or both of these issues may also be takeninto consideration with smaller VCSEL and/or detector arrays.

One or other or both of these issue may be considered where the SPAD orother detector array and VCSEL array are being applied in a system wherepower consumption is desired to be minimized. This may for example be ina mobile communications type application.

In some embodiments, one or other or both of the above discussed issuesmay be addressed by one of more of: providing scanning illumination onthe transmit side by the VCSEL array and providing scanning read-out onthe receive side by the SPAD array.

The transmit scanning may be achieved by one or more of:

-   -   1) An addressable VCSEL array with integrated micro-optics        etched directly into a GaAs substrate which fans out the VCSEL        output to N number of sub-optics in what is termed the primary        optic. Each sub-optic creates the illumination in the desired        portion of the object plane. Each channel may have a dedicated        beam shaping function.    -   2) An addressable VCSEL array with integrated micro-optics        etched directly into a GaAs substrate which fans out the VCSEL        output to a single imaging lens with a focal length designed to        give a FoV (field of view) dependent on the channel separation        in the VCSEL array. The optic has a single beam shaping function        to generate the desired output in the object plane. One beam        shaping function is shared between N channels.    -   3) N VCSELs (optionally with integrated optics) are placed below        N optics. Each optic creates an illumination in the desired        portion of the object plane. This embodiment may make use of a        high precision assembly which can be achieved with methods such        as transfer printing.

These options are described in more detail below.

Some embodiments may provide a scanned read-out with a lower power

VCSEL driver.

Reference is made to FIGS. 1 which shows N addressable channels or beamsprojected into the far field. In the example shown in FIG. 1 there are 6channels 100, 102, 104, 106, 108 and 110. Each of these channelsrepresents a beam which is generated from one or more VCSEL sources. Inthis example there are 6 channels. However, it should be appreciatedthat this is by way of example only and there may be more or less thanthe 6 channels shown. In this example, each channel is shown as beinggenerally rectangular in the X-Y direction. However this is by way ofexample only and in different embodiments, the channels may be of adifferent configuration in the X-Y direction.

Thus in some embodiments, each channel can be provided by a plurality ofVCSELs or a single VCSEL. Each channel will contribute to each sectionof the output. In some embodiments, there is a one to one relationshipbetween a channel in the VCSEL array and a corresponding illuminationpatch or area in the output.

In some embodiments, the channels are provided in turn and in a scanningorder one after the other. In other embodiments, two or more channelsmay be provided at a time. In some embodiments, all of the channels maybe provided at a time. In other embodiments, any order may be used forproviding the channels.

First embodiments will now be described.

Reference is made to FIG. 2 which shows an addressable VCSEL array 112with n channels. This array is provided on a single semiconductor die.This array may provide the channels shown in FIG. 1 or any othersuitable configuration of channels.

The VCSEL array is provided with micro-lenses. The micro-lenses areintegrated as part of the die providing the VCSEL array. Themicro-lenses may be etched directly into the substrate material of theVCSEL (for example GaAs). The lenses may be freeform in surface profile.The micro-lenses may include a diffusing function as well as a lensingfunction.

The micro-lenses 114 are configured to direct each channel to anassociated primary optic component. In particular, the array is made upof N VCSEL sources and each of the N VCSEL sources is provided with amicro-lens. The micro-lens are configured to reduce the divergence ofthe beam provided by each VCSEL source to thereby allow each of the Nchannels to be accommodated. The beams or channels 120 are output fromthe micro-lenses.

In one modification, a micro-lens may be shared by two or more VCSELsources. This may be in an arrangement where a channel is provided by aplurality of VCSEL sources.

The arrangement also comprises a primary optic arrangement 118. Theprimary optic arrangement comprises an array of optics which collimatesand provides a beam shaping function for each channel. The primary opticarrangement 118 comprises input lenses 116, one for each channel. Therespective input lens receives the respective beam 120 and collimatesthat beam. The primary optic arrangement 118 is made up of N sub-opticsto provide a collimation by the input lenses 116 and re-direction andbeam shaping by output lenses 122 to provide respective output beams124. It can be realized with either diffractive or refractive opticalarrangements.

In some embodiments, the number of micro-lenses and the number of inputlenses may be the same. In some embodiments, the number of micro-lensesand the number of input lenses may not be the same. In some embodiments,a micro-lens may be provided for each VCSEL and an input lens for eachchannel, there being one or more VCSELs providing each channel.

The primary optic arrangement 118 is thus configured to beam shape therespective beam and provide output beams 124 which provide the channelssuch as shown in FIG. 1 . The beam shape may be application dependent.In some embodiments, the beam shape may be rectangular. However, inother embodiments a different shaped output may be provided.

In some embodiments, the VCSEL array may be relatively compact. This maybe associated with a reduced cost. The smaller module may beadvantageously integrated with a relative small communications device orthe like. Due to the fact that the VCSEL output is spread out by theintegrated micro-optics, the light can be distributed to the relevantsub-optics without having to increase the die size so that the channelpitch can match the sub-optic pitch which is much larger.

Some embodiments may provide a flexibility in the provided output. The nchannels may be shaped into various channel shapes and field of viewsfor the same underlying VCSEL integrated circuit or chip. The re-shapingcan be achieved with a refractive micro-lens array or a diffractivediffuser or any other suitable arrangement.

Some embodiments may be robust to assembly tolerances. The spacing ofthe sub-optics in the primary optic may be oversized according to theassembly tolerances

Some embodiments are such that the optical power is shared between theVCSEL integrated optics and the primary optics. This may allow for awider field of view but with relatively low index primary optic.

Some embodiments may use a backside emission VCSEL array. In order tointegrate the optics directly into the VCSEL substrate, the VCSEL may bea backside emitter as the light is propagating in the desired directionto allow micro lens integration.

Second embodiments will now be described. Reference is made to FIG. 3which shows another embodiment.

An array 200 of addressable VCSELs is provided. This may be similar tothat discussed in relation to FIG. 2 . The array of VCSELs may provide nchannels.

The array 200 comprises integrated micro-lenses 202. This micro-lensesmay be configured to re-direct each channel or beam provided by theVCSEL array to the primary optic. The micro-lenses may reduce thedivergence to allow for a relatively high f-number (f/#) (f/# is a ratioof the effective focal length to the effective aperture diameter). Thevalue of f/# may be design dependent. In some embodiments, f/# may be upto 16.

In some embodiments, there may be a micro-lens for each VCSEL. In otherembodiments, there may be a micro-lens for each channel. Each channel isprovided by one or more VCSELs.

In some embodiments the micro lenses may be cylindrical micro-lenses.The micro-lenses may have a tilt applied to re-direct the output to theappropriate sub- optic.

The beams 204 output by the micro-lenses 202 may be output to a primaryoptic arrangement 206.

The primary optic arrangement is provided by a single primary optic 208which collimates all the channels with a shared approach. The primaryoptic may be a collimating lens with integrated beam shaping function.The lens may be a refractive lens with a relatively high radius toprovide the collimation. The primary optic arrangement 206 also includesa conformal micro-lens array 209 to produce the diffuser function. Inother embodiments, the primary optic arrangement 206 may be provided bya diffractive optic arrangement.

A beam shaping function is provided by the primary optic arrangement206. The output of the primary optic arrangement 206 comprises Nchannels or beams 210. The use of the single primary optical element 208may employ a smaller lens.

With this arrangement, there may be a reduced divergence. Due to theintegrated optics on the VCSEL, these act to converge the output of theVCSEL. The redirection through VCSEL micro-lens optics may allow for arelatively high f/# primary optic lens design.

This arrangement may be able to support a relatively large number ofchannels. By way of example only, hundreds of channels may be supported.This is facilitated by the use of a single primary optic. This may meanthat the primary optic does not need to scale significantly with thenumber of channels.

In the case where the VCSEL output is highly divergent before theprimary optic, as in the previously described embodiments, then therewill be a lower increase in optical power density when the primary opticis removed versus those options where there are no integrated optics inthe VCSEL and so the output divergence may not be controlled in the samemanner.

Third embodiments will now be described. In another embodiment which isshown in FIG. 4 , the arrangement comprises multiple singulated VCSELdies. Each die comprises one singulated VCSEL source 300. Eachsingulated VCSEL source provides a beam 302 which is provided to aprimary optic arrangement. The primary optic arrangement has a pluralityof optical elements 304, one for each singulated VCSEL source 300. Eachoptical element 304 includes a collimating lens 306 that collimates arespective channel and a beam shaping lens 307 that applies a beamshaping function to provide a respective one of the output beams 306.The output beams may provide the channels shown in FIG. 1 . The beamshaping lenses 307 of the optical elements 304 may fan out the beams toprovide the desired coverage area.

In some embodiments, a lens or other optical component may be providedon each VCSEL die. However, other embodiments may not require an opticalcomponent to be integrated with the VCSEL.

With the arrangement of FIG. 4 , it is desirable to ensure that eachVCSEL die 300 is aligned with respect to one another and with respect tothe respective optical element 304. In this regard, reference is made toFIGS. 5 a and 5 b.

FIG. 5 a illustrates a scenario where the VCSEL dies are correctlyaligned but there is a misalignment between the VCSEL dies and theprimary optical arrangement. In FIG. 5 a , the output channels or beamsare referenced 504, 506 and 508. These are the beams output by theprimary optic arrangement. The target location for these beams isreferenced 502 and represents where the beams should be located. As canbe seen, from FIG. 5 a , if all the VCSEL dies are misaligned withrespect to the primary optic arrangement by the same amount then alloutput channels will have an equal angular offset with respect to thetarget 502. In some applications, the misalignment may for exampleapproximately 4 degrees for a misalignment of 1 mm.

FIG. 5 b illustrates a scenario where the VCSEL dies are misaligned butthere is no misalignment between the VCSEL dies and the primary opticalarrangement. In FIG. 5 b , the output channels or beams are referenced512, 514 and 516. These are the beams output by the primary opticarrangement. The target location for these beams is referenced 510 andrepresents where the beams should be located. As can be seen, from FIG.5 b , if the VCSEL dies are offset by differing amounts there will be anangular offset or gaps between output beams. In some applications, themisalignment may for example approximately 4 degrees for a misalignmentof 1 mm.

It may even be possible to have a scenario where the VCSEL dies aremisaligned and there is misalignment between the VCSEL dies and theprimary optical arrangement.

Some embodiments utilize the assembly technique known as ‘transferprinting’ With this technique, it is possible to achieve a relativelyhigh VCSEL to VCSEL die alignment accuracy (+/−2 μm). Transfer printingis a wafer scale process that allows alignment of individual die withrespect to each other to be of the same order as wafer alignmenttolerances. Since, as detailed above, the alignment is of the VCSEL dierelative to each other so the transfer printing process may enableeffective implementation of these embodiments.

Some embodiments may have the advantage that this arrangement isscalable to as many channels as desired. A main limitation may be thesize of the module in the X/Y directions.

Some embodiments may prove a relatively high resolution system with thecombination of the micro-lenses integrated into the VCSEL array and theprimary optic arrangement. It should be appreciated that in someembodiments, one or other of the micro-lenses and the primary lenssystem may be omitted. This may be for systems which are desired to havea lower resolution.

Some embodiments may provide better laser safety in the case that theprimary optic falls out. In the case where the VCSEL output is highlydivergent before the primary optic then there will be a lower increasein optical power density when the primary optic is removed versus theembodiments where there are no integrated optics in the VCSEL.

In the above described embodiments, the substrate has been described asbeing of GaAs. However, it should be appreciated that this is by way ofexample only and different materials may be used for the substrate indifferent embodiments.

It should be appreciated that first embodiments, second embodiments andthird embodiments have been described. Features described in relation toone embodiment may be used with other embodiments.

Reference is made to FIG. 7 which schematically shows a detector 704.The detector has a VCSEL array. The VCSEL array may be any of thepreviously described arrangements. The detector has a SPAD or othersuitable detector array 702 which is configured to receive light whichhas reflected off an object.

Control circuitry 706 is provided which is configured to control theVCSEL array and/or the SPAD array. The control circuitry may beconfigured to control which row or rows of the VCSEL array is activated.The control circuitry may control the SPAD array.

It should be appreciated that the above described arrangements may beimplemented at least partially by an integrated circuit, a chip set, oneor more dies packaged together or in different packages, discretecircuitry or any combination of these options.

Various embodiments with different variations have been described hereabove. It should be noted that those skilled in the art may combinevarious elements of these various embodiments and variations.

Such alterations, modifications, and improvements are intended to bepart of this disclosure, and are intended to be within the scope of thepresent disclosure. Accordingly, the foregoing description is by way ofexample only and is not intended to be limiting.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

1. An apparatus, comprising: a plurality of singulated vertical-cavity surface-emitting laser dies each configured to output light; and an optical arrangement configured to receive light from the vertical-cavity surface-emitting lasers and to output a plurality of output light beams, the optical arrangement including one or more collimators configured to provide one or more collimated beams by collimating the light from the plurality of the vertical-cavity surface-emitting lasers and sub-optics configured to produce the plurality of output light beams by beam shaping the one or more collimated beams.
 2. The apparatus as claimed in claim 1, wherein the sub-optics include an array of optical elements configured to produce the plurality of output light beams.
 3. The apparatus as claimed in claim 1, wherein the one or more collimators comprises a shared optical element which is configured to receive light from each of the vertical-cavity surface-emitting lasers of the array.
 4. The apparatus as claimed in claim 1, wherein the one or more collimators comprises a plurality of collimating lenses configured to produce plural collimated beams of the one or more collimated beams from the light received from the plurality of the vertical-cavity surface-emitting lasers.
 5. The apparatus as claimed in claim 4, wherein the vertical-cavity surface-emitting lasers are configured to produce a plurality of input light beams and the one or more collimators comprises an array of collimating lenses respectively for each input light beam, one or more of the plurality of the vertical-cavity surface-emitting lasers being configured to provide each light beam.
 6. The apparatus as claimed in claim 1, further comprising one or more micro-lenses provided on a substrate providing the array of vertical-cavity surface-emitting lasers.
 7. The apparatus as claimed in claim 1, further comprising a plurality of lenses on the array of vertical-cavity surface-emitting lasers, one for each of the vertical-cavity surface-emitting lasers.
 8. The apparatus as claimed in claim 1, further comprising a plurality of micro-lenses provided on a substrate providing the array of vertical-cavity surface-emitting lasers, wherein the one or more collimators includes a shared collimating lens which is configured to receive light from each of the vertical-cavity surface-emitting lasers of the array.
 9. The apparatus as claimed in claim 1, further a plurality of micro-lenses provided on a substrate providing the array of vertical-cavity surface-emitting lasers, the micro-lenses being configured to provide a plurality of input light beams, wherein the one or more collimators includes a plurality of collimating lenses, one collimating lens being provided for each input light beam.
 10. The apparatus as claimed in claim 1, wherein the array of vertical-cavity surface-emitting lasers includes a plurality of singulated vertical-cavity surface-emitting laser dies, the singulated vertical-cavity surface-emitting laser dies being configured to provide a plurality of input light beams, and the one or more collimators comprises a plurality of collimating lenses, one being provided for each input light beam.
 11. The apparatus as claimed in claim 1, comprising control circuitry configured to control which of the vertical-cavity surface-emitting lasers are activated.
 12. The apparatus as claimed in claim 11, wherein the control circuitry is configured to control the array of vertical-cavity surface-emitting lasers to provide input light beams sequentially to the optical arrangement.
 13. A detector, comprising; an apparatus configured to direct output light toward an object, the apparatus including: an array of vertical-cavity surface-emitting lasers, each of the vertical-cavity surface-emitting lasers being configured to be a source of light; and an optical arrangement including a primary optical lens configured to receive light from a plurality of the vertical-cavity surface-emitting lasers and to output a plurality of collimated beams, the optical arrangement including sub-optics configured to produce a plurality of output light beams by beam shaping the one or more collimated beams; and a light detector configured to detect light reflected from the object.
 14. The detector as claimed in claim 13, wherein the light detector comprises an array of single photon avalanche diodes.
 15. The detector as claimed in claim 13, further comprising a processor configured to calculate a distance between the detector and the object.
 16. The detector as claimed in claim 15, wherein the processor is configured to calculate a phase shift between the light produced by the array of vertical-cavity surface-emitting lasers and the light reflected from the object.
 17. An apparatus, comprising: an array of vertical-cavity surface-emitting lasers, each of the vertical-cavity surface-emitting lasers being configured to be a source of light; and an optical arrangement configured to receive light from the array of vertical-cavity surface-emitting lasers and to output a plurality of output light beams, the optical arrangement including a primary optical lens configured to receive the light from the light and to provide one or more collimated beams by collimating the light from the plurality of the vertical-cavity surface-emitting lasers and a micro-lens array configured to produce the plurality of output light beams by beam shaping the one or more collimated beams.
 18. The apparatus as claimed in claim 17, comprising a light detector configured to detect the output light beams from the optical arrangement.
 19. The apparatus as claimed in claim 18, comprising a processor configured to calculate a distance between the light detector and an object.
 20. The apparatus as claimed in claim 19, comprising an array of single photon avalanche diodes coupled to the processor. 